The invention relates to stacks of cassettes, and in particular to stacks of cassettes which are designed to receive conductors. In the present description, conductors mean both elements in the form of wires or strips in which light can be propagated, among others optical fibres, and elements in the form of wires or strips for conducting electricity, among others metal wires, which for example are made of copper, or copper telephone wires.
In telecommunications, optical fibres are organised in a stack of cassettes. In general, each cassette comprises a base and two lateral walls. A baffle which defines a path is provided on the base, and makes it possible to comply with the constraints of minimum radius of curvature of the conductors. In general, each cassette comprises a lateral inlet and an outlet for the conductors.
A stack of cassettes is already known which is articulated on one side, in pairs, by a flexible hinge. A cassette can be kept open at approximately 90xc2x0 from the cassette beneath it by means of a hook extending from a lateral wall of the upper cassette, which is placed behind a boss provided on a lug which extends from the edge of the lower cassette. The upper cassette cannot go beyond aposition of 90xc2x0, owing to the fact that stop elements are provided on the two opposite edges of the two cassettes.
A stack of cassettes of this type enables the operator to work with his hands free, when he opens the cassette, but has the disadvantage that it does not allow the cassette to be opened from one side or the other of the cassette, as required.
The invention eliminates this disadvantage.
The object of the invention is a stack of at least two cassettes which are articulated in pairs, and each comprises a base and two lateral walls. For each cassette, a first shaft extends parallel to one of the lateral walls, and spaced from the latter towards the exterior, and a second shaft extends parallel to the other one of the lateral walls, and spaced from the latter towards the exterior. Each shaft is supported by at least one lug, which extends from the lateral wall, and is shaped such as to define in succession, from the lateral wall towards the exterior, a first recess and a first catch, and a second recess and a second catch. A detachable rigid connector bar has a branch which ends in a fork, which snaps onto the first shaft (or the second shaft) of two adjacent cassettes. The lug of a first cassette is disposed relative to a lug of a second cassette, adjacent to the first cassette, such that, when the connector bar is snapped onto the first shafts (or second shafts) of the two cassettes, the rotation of the first cassette relative to the second cassette around the first shaft (second shaft) of the first cassette, makes the first catch of the lug of the first cassette come into the first recess of the lug of the second cassette, and/or makes the second catch of the lug of the first cassette come into the second recess of the lug of the second cassette.
By eliminating a flexible hinge, by rendering integral with the cassette shafts which can extend along two edges, which for example are opposite, of the cassette, and by providing a rigid connector bar, an articulation is obtained which can be provided on one side or the other of the cassette, as required. The snapping of the first catch of the upper cassette, which has tilted into the first recess of the lower cassette, makes it possible to keep the upper cassette open for example at 90xc2x0 from the lower cassette, the snapping preventing a larger angle from being assumed. The same applies to snapping of the second catch.
Preferably, one of the branches of the connector bar has a wall which is substantially parallel to the lateral wall of the cassette in question. The connector bar cannot rotate around the shaft which is held in this branch, and the movement of opening can be carried out flawlessly, the connector bar being rendered integral with the cassette, without any degree of freedom in rotation.
Preferably pair of lugs extends from each lateral wall, the distance between the two lugs of the pair being slightly greater than the width of the connector bar. The connector bar is thus prevented from sliding along the shaft Preferably, six lugs extend from each lateral wall. The six lugs are arranged in two groups that each contain three lugs. This makes it possible to fit two connector bars between each group of three lugs.
A locking clip is also provided, which makes it possible to keep the cassettes on top of one another, on the side opposite to that on which they can tilt.